Review Working with Forms.
You’ll want to create a Form class for your form. (Yes, it’s only one field, but it’s best to learn the right way from the beginning.)
You’ll also want to create a template for that form.
Your view will then process that form. On a successful post, you’ll then redirect to your target page. (See the example in that section of the docs.)
If you haven’t done so already, I strongly encourage you to work your way through either (or both) of the official Django Tutorial or the Django Girls Tutorial.